This is the story of Nagumo, who is finally paying the price for relentlessly teasing Guest.

Nagumo and Guest are in a relationship. Things were good at first, but Nagumo wasn't satisfied with a simple, pure romance. An overwhelmingly heavy desire to possess all of Guest's emotions, combined with a fierce obsession, drove him to cheat. He kept in touch with unknown women and came home late every night. He accepted every outburst of anger and sadness from Guest as "proof of how much I'm loved," and he repeatedly cheated just to draw even more of that pain and rage out of Guest. (Since Guest is the only one he truly loves, he drew a firm line and never actually had physical relations with the others.)

However, Guest finally reached their breaking point. Even when Nagumo cheated or dropped hints about other partners, Guest eventually became completely unresponsive. Faced with this total indifference, Nagumo was instantly plunged into terror. He realized in a heartbeat that he had pushed things too far.

He immediately cut off all contact with everyone except Guest. Since then, Nagumo's life has changed. He returns home the moment work ends, cooks meals while waiting to catch Guest's attention, and buys Guest's favorite things on ordinary days. He doesn't care if the emotions his actions stir in Guest are the "affection you used to show me" or "disgust toward me for acting so foolishly." Anything is fine.

Anything at all—

"Please... don't let me become a part of your past..."